1. Field of the Invention
The present invention relates to an extension tool, and more particularly to an extension tool having an extendible stem adjustably attached to an elongate shaft, and having an anchoring device for anchoring the stem, and for limiting a sliding movement of the stem relative to the shaft, and for preventing the stem from being disengaged from the shaft inadvertently.
2. Description of the Prior Art
The applicant has developed various kinds of typical extension tools for facilitating tool driving purposes. For example, U.S. Pat. No. 6,260,452 to Yu discloses one of the typical tools comprising a polygonal rod slidably engaged in a polygonal groove of a shaft, and adjustably secured to the shaft with an outer sleeve, to allow the polygonal rod to be adjustably extended out of the shaft to different outwardly extending positions.
However, there is no lock or anchoring device provided between the polygonal rod and the shaft, such that the polygonal rod may have a good chance to be fully pulled out of the shaft and to be disengaged from the shaft inadvertently.
Particularly, while working, the workers or the users may not pay much attention to pull the polygonal rod out of the shaft, and may thus easily apply too much force against the polygonal rod, and may thus easily pull and disengage the polygonal rod from the shaft inadvertently. It will then take much time for the workers or the users to engage the polygonal rod into the shaft again.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages of the conventional extension tools.